Shoe sole structure



May 2, 1944. c. R. HILL SHOE SOLE STRUCTURE Filed Sept. 18

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M W P. m M H c ATTO/P/VE y- Patented May 2, 1944 UNITED STATES ATENT OFFICE Application September 18, 1942, Serial No. 458,810 In Canada October 4, 1941 7 Claims.

This invention relates to shoes and more par ticularly to an improved sole structure therefor.

The advisability of providing an absolutely Waterproof sole structure for shoes is obvious and many such structures have been proposed. Most, if not all, of these structures include as an element thereof a non-porous waterproof layer. Such a layer destroys the effect of the porous characteristics of leather soles, which permit ventilation and the evaporation of moisture therethrough. These waterproof structures are, therefore, subject to the same disadvantages which are found in the use of rubber-soled shoes, namely, that a discomfort and burning of the feet occurs because of the non-ventilated character of the structure and the impossibility of moisture evaporation therethrough.

It is an object of the present invention to provide a waterproof sole structure through which ventilation and the evaporation of moisture may occur. This and other objects and advantages of the invention will be apparent from the following description with reference to the accompanying drawing, in which,

Figure 1 is a bottom view of a sole structure with outsole removed;

Figure 2 is a sectional side elevation;

Figure 3 is a sectional side elevation of a slightly modified form;

Figure 4 is an enlarged sectional view of a sole interlayer;

Figure 5 is a perspective view of the sole interlayer;

Figure 6 is an enlarged sectional View of an other form of sole interlayer;

Figure '7 is a perspective View of another form of sole interlayer, and

Figure 8 is a perspective view of still another form of sole interlayer.

Referring to the drawing wherein a shoe structure is illustrated, l represents the upper, 2 the Welt, 3 the insole, 4 the outsole, 5 the heel and 6 a sole interlayer produced and arranged in the sole structure in accordance with the invention. .The structure of Figures 1 and 2 includes a slip sole 1 as commonly employed in shoes. Moreover, the usual filler layer, not shown, may be incorporated.

When a slip sole is employed, as shown in Figures 1 and 2, the interlayer 6 is preferably arranged between the outsole and the slip sole but when there is no slip sole, the interlayer is arranged between the insole and outsole as illustrated in Figure 3.

The interlayer may, for convenience, extend throughout the entire sole instep and heel portions, as shown in Figures 1 and 2, or it may extend only throughout the sole and instep portions terminating adjacent the heel, as shown in Figure 3. Furthermore, it may, if desired extend to the edge of the outsole but it preferably terminates at or adjacent the edge of the insole, as shown in Figures 1, 2 and 3.

The interlayer may be fixed in position by the application of a suitable rubber cement to a marginal area thereof indicated at 8. The cement is applied to either the top or bottom surface or both surfaces and results in the firm adhesion of such surfaces to the adjoining surface of shoe sole.

One type of interlayer, as shown in Figures 4 and 5, comprises a thin sheet of rubber 9 having a plurality of punctures l9 therein consist ing of small cuts or breaks in the rubber as made by a sharp-pointed or sharp-edged tool, such as indicated at H in Figure 4, no portion of the sheet being cut out. Each break is of small extent, preferably of one-thirty-"second inch or less in length. It has been found that such a sheet does not permit the passage there through of water but does permit ventilation or passage of air and vapour.

Another type of interlayer is shown in Fig ure 6 and comprises a thin sheet of rubber l2 having a plurality of perforations l3 therein. The perforations are preferably of one=thirtysecond inch or less in diameter. It has been found that such a sheet, while permitting freely the passage of air or vapour, has great resistance to the passage of water through the perforations due to surface tension or capillary attraction.

A further form of interlayer is shown in Figure 7 and consists of a sheet M of fibrous mate'- rial such as cotton fabric or canvas having a coating l5 applied thereto. The coating It does not fill or seal the pores or mesh of the sheet but coats and Waterproofs the threads or fibres of the sheet without actually sealing the latter. The coating is applied by dipping the sheet in a suitable waterproofing solution. A satisfactory solution for the purpose comprises rubber and wax dissolved in a hydrocarbon solvent, preferably petroleum naphtha. Well-milled crepe rubber is dissolved in the solvent with the wax in the preferred proportions of 2 ounces of rubber and 2 ounces of paraffin or like wax perv imperial gallon of solvent. After immersion of the sheet in the solution and evaporation of the solvent therefrom, the individual threads or fibres of the sheet are left in a coated waterproofed condition although the pores of the sheets are not sealed. Such a sheet, while permitting breathing or ventilation therethrough, is highly resistant to the passage of water.

A preferred form of interlayer is shown in Figure 8 and comprises a pair of superimposed sheets [6 and I! of heavy creped paper having a waterproof coating l8 on one side thereof. A satisfactory commercially available paper is one known as 60 lb. asphalt-coated creped kraft. The asphaltic coating is quite thin and flexible and does not affect the pliability of the paper. While such an asphaltic coating provides an efficient waterproofing medium for the paper, it will be understood that other waterproofing impregnating or coating agents for the paper, such as, for instance, that described with respect to the interlayer shown in Figure 7, may be employed.

It is important that a creped paper be employed to permit stretching of localized areas of the interlayer during flexing movements of a shoe equipped therewith. The above referred to commercially available paper allows a stretching movement, which has been found to be sufficient for the present purpose. It will also be apparent that the creped character of the interlayer will impart a cushioning effect to the shoe sole.

The sheets 55 and II have a plurality of rows [9 of closely spaced needle punctures therein. While a multiplicity of such punctures is desirable, it will be obvious that the spacing of the punctures from each other may vary within wide limits. By way of example, it may be stated that rows one-quarter inch apart with punctures one-eighth inch apart in such rows has been found satisfactory. Moreover, while a sheet having needle punctures is preferably employed, it will be understood that a sheet having a multiplicity of punched-out perforations of one-thirtysecond inch or less in diameter may be used.

While the use of cement on a small marginal area of the interlayer, as shown in Figure 1, has been proposed, it is preferable that little or no cement be used in the assembly of the interlayer and shoe sole. The interlayer may extend to, or substantially to, the edge of the outsole and nails may be temporarily employed to hold it in place. The usual stitching of the sole members may extend through the interlayer to fix it finally in position.

A layer of rubber cement is frequently employed between the out and slip soles of shoes (1) to prevent squeak and (2) to provide a temporary means for holding the out and slip soles in position for stitching. It is advisable that the use of such cement be eliminated in shoes treated in accordance with the present invention since the presence of such cement may adversely affect the air permeability of the sole structure. The use of temporarily placed nails serves as a satisfactory holding means, while the interlayer of the present invention acts to prevent squeak.

In assembling the sole structure, the coated side of one sheet of the interlayer is positioned to face the inner side of the outsole and the coated side of the second sheet is positioned to face the uncoated side of the first sheet.

It is important that the general direction of the creping in each sheet of the interlayer should be from side to side rather than from toe to heel since it is obvious that the stretch characteristic of the interlayer should be in the latter direction. While the interlayer has been described as consisting of two sheets, it is apparent that one sheet only may be employed in cases where a light waterproof layer will suffice.

In the manufacture of new shoes in accordance with the invention, it is advisable that the interlayer should extend throughout the entire sole and heel area of the shoe. If the shoes are treated after manufacture in either new or used state, the interlayer may extend only throughout the sole area, terminating adjacent the heel.

It has been found that shoes embodying the sole interlayer in accordance with the invention are quite Waterproof in actual use While being unattended by the disadvantages previously referred to. Moreover, it has been found that such a layer constitutes an anti-squeak element in shoe soles.

I claim:

1. A sole interlayer for shoes comprising a sheet of creped paper having a waterproof coating on one side thereof and a multiplicity of punctures therein, said punctures being substantially uniformly disposed throughout the sheet.

2. A sole interlayer for shoes comprising a sheet of creped paper having a waterproof coating on one side thereof and a multiplicity of minute incisions therein, said minute incisions being substantially uniformly disposed throughout the sheet.

3. A sole interlayer for shoes comprising a sheet of creped paper having a waterproof coating on one side thereof and a multiplicity of perforations therein, said perforations being substantially uniformly disposed throughout the sheet. 7

4. A sole interlayer for shoes comprising a sheet of creped paper having an asphaltic coating on one side thereof and a multiplicity of punctures therein, said punctures being substantially uniformly disposed throughout the sheet.

5. In a shoe sole structure having an insole and an outsole, an interlayer between said insole and outsole, said interlayer comprising at least one sheet of creped paper having an asphaltic coating on one side thereof and a multiplicity of punctures therein, said sheet being disposed with the coating thereon facing the inner surface of said outsole.

6. In a shoe sole structure having an insole and an outsole, an interlayer between the insole and outsole extending throughout the major surface area of the outsole and comprising at least one sheet of paper having a waterproof coating thereon and a multiplicity of air passages extending therethrough, said passages being of sufficiently small cross-sectional area to substantially prevent by surface tension passage therethrough of waterseeping through the outsole into contact with the interlayer.

7. In a shoe sole structure having an insole and an outsole, an interlayer between said insole and outsole extending throughout the major surface area of the outsole and comprising a pair of superimposed sheets of creped paper each having a waterproof coating on one side thereof and a multiplicity of perforations therein, the

diameter of said perforations not substantially exceeding one-thirty-second inch.

CHARLES RAPELJE HILL. 

